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Microphone output level
Estimate microphone RMS voltage and ideal preamp output from sensitivity, sound pressure and gain.
Sensitivity (mV/Pa): 0.1–100; Sound pressure level (dB SPL): 20–150; Preamp gain (dB): 0–80
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Microphone output level
Sensitivity (mV/Pa): 2.8 Sound pressure level (dB SPL): 94 Preamp gain (dB): 40
- Microphone RMS voltage (mV)
- 2.806649
- Ideal preamp output (dBu)
- -8.822274
Pressure p = 20 × 10^−6 × 10^(SPL/20) Pa; microphone RMS voltage in mV = sensitivity × p; ideal preamp output = 20 log10[(mV/1000)/0.775] + gain dBu. The reference is 20 µPa for SPL and 0.775 V RMS for 0 dBu, consistent with the level converter. One pascal is 93.979400 dB SPL, commonly rounded to 94 dB. Enter sensitivity 0.1–100 mV/Pa, unweighted RMS sound level 20–150 dB SPL at the capsule, and gain 0–80 dB; fractions are allowed. Sensitivity is usually specified at 1 kHz with an open circuit; this ideal linear estimate excludes loading, frequency response, pads, noise, distortion, microphone overload and preamp clipping. It does not establish safe sound levels, required gain, headroom, ADC dBFS or real equipment ratings. Check actual specifications and meters; numeric limits are not operating recommendations. Six decimals without intermediate rounding.
Methodology
How it works
Pressure p = 20 × 10^−6 × 10^(SPL/20) Pa; microphone RMS voltage in mV = sensitivity × p; ideal preamp output = 20 log10[(mV/1000)/0.775] + gain dBu. The reference is 20 µPa for SPL and 0.775 V RMS for 0 dBu, consistent with the level converter. One pascal is 93.979400 dB SPL, commonly rounded to 94 dB. Enter sensitivity 0.1–100 mV/Pa, unweighted RMS sound level 20–150 dB SPL at the capsule, and gain 0–80 dB; fractions are allowed. Sensitivity is usually specified at 1 kHz with an open circuit; this ideal linear estimate excludes loading, frequency response, pads, noise, distortion, microphone overload and preamp clipping. It does not establish safe sound levels, required gain, headroom, ADC dBFS or real equipment ratings. Check actual specifications and meters; numeric limits are not operating recommendations. Six decimals without intermediate rounding.
Method and assumptions documented by Techrider.live
2026-11-04
Frequently asked questions
Can this predict whether the input will clip?
No. Compare measured levels with the actual microphone and preamp limits, including pads and loading. RMS voltage does not determine transient peaks, and dBu is not dBFS.